Method for spreading powder and device therefor

ABSTRACT

A device for spreading powder in which air under pressure carrying a pulverulent treating agent in the form of powder and/or granular material is forced into a soft and light tubular pipe from one end or both ends thereof and discharged or spread downwardly through a plurality of nozzles disposed spaced apart from each other longitudinally of the tubular pipe.

United States Patent METHOD FOR SPREADING POWDER AND DEVICE THEREFOR 6Claims, 12 Drawing Figs.

US. Cl 239/146, 239/188, 239/195, 239/547, 239/561, 239/567 int. Cl B05b9/02 Field of Search 239/195,

References Cited UNITED STATES PATENTS Aschenbrenner Hauck Meek AlbanoHijiya McLhinney Ross Babington Pierce Primary Examiner-Lloyd L KingAttorney-McGlew and Toren 239/547 239/566 X 239/561 X 239/547 X 239/547X 239/567 X 239/561 X 239/547 X ABSTRACT: A device for spreading powderin which air under pressure carrying a pulverulent treating agent in theform of powder and/or granular material is forced into a soft and lighttubular pipe from one end or both ends thereof and discharged or spreaddownwardly through a plurality of nozzles disposed spaced apart fromeach other longitudinally of the tubular pipe.

PATENTED 0m 5 Ian SHEET 1 UF 3 A F/GJ n M 0 7/ N X D E v o K2 4680N h$000%0 n a WV N c w w J l .J .W Y H B rwr w 1 w M w w a on my 7 0 5 w 0I lllll asss a Nal0 N020 M130 NM) M50 M60 lmwosg SPREAD/N6 mcnme NOZZLEr nggmornmmm I INVEN'I'UR. manna SUM PATENTEDUBT Susan 3,610,530

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METHOD FOR SPREADING POWDER AND DEVICE THEREFOR This is a division ofapplication Ser. No. 723,449, filed Apr. 23, 1968.

BRIEF SUMMARY OF THE INVENTION The present invention relates to a devicefor spreading powder.

In the specification, it is to be understood that powder refers topowder, granular material and a mixture of powder and granular material.In the conventional work of spreading agricultural chemical agents suchas herbicides, insecticides, fungicides, etc., an operator carrying apowerdriven spreading machine on his shoulder spreads the agents througha pipe connected by a universal joint to the machine. In the case ofspreading a large quantity of the agents over a large area, a helicopteror a light plane is employed to spread the agents from the air over apredetermined area. However, in the former use of manual spreading, theoperator must move around the whole area for spreading the agents sothat the manual spreading operation involves very hard labor, butresults in less productivity. In the latter case of employing ahelicopter or a light plane, the cost is very high with less spreadingefficiency so that this method cannot be employed on a small farm as anadvantageous or economical method.

In view of the above, the fundamental object of the present invention isto eliminate the drawbacks in the conventional agricultural chemicalagent spreading device as described above. Another object of the presentinvention is to provide a method for spreading powder characterized byforcing air under pressure, carrying an agent in the form of powder,into at least one terminal of a soft and light hose, and discharging orejecting downwardly the air carrying the agent in the form of powderand/or granular material from a plurality of nozzles disposed spacedapart from each other longitudinally of the hose.

Still another object of the present invention is to provide a device forspreading powder characterized in that one side of a soft and light hoseis provided with a plurality of nozzles spaced apart from each otherlongitudinally of the hose, and one end of the hose is coupled to meansfor discharging air carrying an agent in the form of powder and/orgranular material.

The present invention is more particularly directed to a device forspreading powder in which, as a spreading hose, is used an elongatedtube made of soft plastic film such as polyethylene, polypropylene, etc.having a very thin wall thickness: this hose is provided with a suitablenumber of small apertures for discharging or ejecting powder or thelike, spaced apart from each other by a suitable distance; these smallapertures are so arranged and disposed that they are directed downwardlywhen the hose is extended for spreading operation; and one end of thehose is closed in any suitable manner such as by welding, fastening,etc. while the other end of the hose is coupled through a suitablecoupling to a discharge port of a power-driven spreading machine.

The operation of the spreading device according to the present inventionis as follows. First, the power-driven spreading machine is activated.When the air is discharged or ejected through the small apertures of thehose against the ground, the reaction force of the air jet acts upon thehose so as to give buoyancy to the hose, thereby holding the hose at acertain level above the ground.

At the same time, the agricultural chemical agents carried by the airunder pressure are discharged or spread through the small apertures ofthe hose. Therefore, when the hose is moved in a suitable direction in asuitable manner, while the agents are being discharged or spread asdescribed above, a uniform and effective spreading operation can beaccomplished.

To-facilitate an understanding of the present invention, FIG. 5 showsthe characteristic curves of the spreading powders of the devices of thepresent invention and of the prior art,

respectively. The parameter of the characteristic curve is the speed ofmoving the device. The hatched portion a in the figure indicates thespreading time per unit area when a conventional shoulder-typepower-driven spreading machine only is used; the hatched portion b, thespreading time per unit area when a spreading hose according to thepresent invention is attached to the spreading machine; and the hatchedportion 0, the spreading time per unit area when a spreading hoseaccording to the present invention is attached to a farm duster. Whenonly a shoulder-type power-driven spreading machine is used in aconventional method, the spreading range is approximately 10 meters atthe most, even if the operator extends his hand to the full. However,when a spreading hose according to the present invention is usedtogether with the power-driven spreading machine, the spreading rangecan be extended as far as meters and spreading time can be reduced tosuch an extent that it is beyond comparison. Thus, it will be clearlyunderstood that the method and device for spreading powder according tothe present invention has an extremely high performance as compared withthe conventional methods and devices.

BRIEF EXPLANATION OF THE DRAWINGS FIG. 1 is a front elevation view of aspreading hose used in the present invention;

FIG. 2 is a bottom view thereof;

FIG. 3 is a view of a general embodiment of a powder spreading deviceaccording to the present invention;

FIG. 4 is a front elevation view of a spreading hose in its wound state;

FIG. 5 graphically illustrates the characteristic performance curves ofvarious spreading devices;

FIG. 6 graphically illustrates the pressure distribution, the dischargedistribution, the buoyancy distribution and the airflow ratedistribution along the longitudinal direction of a spreading hoseconstructed according to the first embodiment of the present inventionshown in FIG. 1,2 and 3.

FIGS. 7, 8, 9 and 10 show various respective embodiments of the presentinvention for ensuring the uniform spreading; and

FIGS. 11 and 12 show respectively two embodiments of a spreading hose,according to the present invention, in which the inner wall surface ofthe spreading hose is provided with a plurality of barrier projectionsspaced apart from each other by a suitable distance in order to causewavering and vortex motions of the air carrying the agriculturalchemicals such as herbicides, insecticides and fungicides, therebyensuring the effective spreading operation of said agriculturalchemicals containing granular agents, FIGS. I l-I and 12-I being bottomviews while FIGS. Il-II and l2-II are sectional views taken along thelines xX of FIGS. 11-1 and 12-I, respectively.

DETAILED DESCRIPTION OF THE INV ENTION A powder spreading devicetherefor according to the present invention will be best understood fromthe following description taken in conjunction with the accompanyingdrawings, in which the most general embodiment of the present inventionis shown in FIGS. 1, 2 and 3. A spreading hose 1 made of thinpolyethylene has a plurality of small apertures 2 at the bottom sidethereof for discharging or ejecting the agricultural chemicals. One end3 of the spreading may be closed in a suitable manner but the other endof the spreading hose 1 is coupled through a coupling 4 to a dischargeport 6 of a power-driven spreading machine 5. When the spreading hose 1is not in use, it is a flattened tube and may be folded or wound like abelt for storage as shown in FIG. 4. When spreading work is to be made,the spreading hose 1 is extended over the ground. When the power-drivenspreading machine 5 is started, the spreading hose 1 is expanded roundand the air is discharged or ejected from the small apertures 2 togetherwith the agricultural chemicals. At the same time, the reaction of theejected flow of the air acts as buoyancy upon the spreading hose I sothat the spraying hose 1 is caused to float over the ground as soon asthe spreading machine 5 is driven, whereby the spreading hose 1 can bemaintained at a level or height above the ground while the agriculturalchemical powders are being spread.

Thus, when the spreading hose 1 is located at a right angle relative tothe direction of movement of the spreading hose 1, the spreadingoperation can be effected instantaneously in a width equivalent to thelength of the spreading hose 1. When the spreading hose 1 is inclinedrelative to its direction of movement, a spreading hose holder on thelee side is protected from being exposed to the spread chemical powderseven when the wind blows at a right angle relative to the direction ofmovement of the spreading hose 1. Another advantage of positioning thespreading hose 1 angularly of the direction of its movement is thatnonuniform spreading over the whole length of the spreading hose can beeliminated even if the spreading hose 1 is throttled or closed partiallybecause it is too long.

FIG. 6 shows the performance characteristic curves of a spreading deviceconstructed according to the first embodiment of the present inventionshown in FIGS. 1, 2, and 3. The spreading hose 1 having the length of 20m. was made of a soft polyethylene film having a thickness of 0.08 mm.(approximately 0.032 inch) and a mean diameter of 40 mm. (1 37/64inches). The pitch of the small apertures was 300 mm. (approximately ISinches), and the numbers and diameters of the small apertures from theends coupled to the power-driven spreading machine to the center of thespreading hose were 52 X 8 mm., l X 10mm., 25 X15 mm., and 2 X19 mm.

In case of a spreading hose having a length of I00 meters, the spreadinghose was made of a soft polyethylene film having a wall thickness of 0.1mm.

The mean diameter of the spreading hose was 125 mm., and the pitch ofthe small apertures was 500 mm. The numbers and diameters of the smallapertures from the ends coupled to the power-driven spreading machinesto the center of the spreading hose, 15 X 5 mm., 65 X 6 mm., 45 X 7 mm.,25 X 8 mm., 20 X10 mm., x11mm.,10 X13 mm., and 5 X14 The most importanttechnical problem encountered in the practical use of a powder spreadingdevice according to the present invention is to uniformly spread thepowder. It is imperative that the powders should be spread uniformlyover the whole length of the spreading hose. When the diameter of thehose is fixed and the pitch of the small apertures is constantthroughout the whole length of the hose, the flow rates of the air fromthe small apertures will be reduced at the small apertures approachnearer to the end of the hose remote from the spreading machine so thatthe discharge of the agricultural chemical powder carried by the airdischarged through these small apertures will be reduced accordingly.

Thus, it is necessary to increase the diameters of the small aperturesas they approach to the end of the spreading hose remote from thespreading machine when a pitch is fixed over the whole length of thespreading hose; to decrease the pitches as the small apertures approachto the end of the spreading hose remote from the power-driven spreadingmachine when the diameter of the small aperture is fixed; or to decreasethe inner diameters of the spreading hose as it nears to the end thereofremote from the power-driven spreading machine.

FIGS. 7, 8, 9 and 10 illustrate some embodiments of the presentinvention for effecting the uniform spreading of the agriculturalchemical powders. In the embodiment shown in FIG. 7, the diameter of thesmall apertures is fixed while the pitches thereof are decreasedcontinuously or in steps. That is, when the diameter of the spreadinghose is fixed throughout the whole length thereof and the diameters ofall of the small apertures are equal, the discharge of the agriculturalchemical powders through the small apertures decreases gradually as thesmall apertures approach from the coupling to the end remote from thepower-driven spreading machine. Therefore, the quantity of the powdersupplied or spread over an object is varied. However, when the pitchesof the small apertures are made shorter, the quantity of the powderssupplied or spread per unit length of the spreading hose, that is overunit area of an object, can be maintained constant over the whole lengthof the spreading hose.

That is, when d a d,.= const., the pitches are continuously decreased asshown by the relation of:

or the pitches are decreased in step as shown by the relation of:

FIG. 8 shows an embodiment of the present invention in which thediameters of the small apertures are decreased continuously or in stepswhile the pitch is maintained constant. When the inner diameter of thespreading hose is maintained constant and the pitch of the smallapertures is also kept constant, the inner pressure of the spreadinghose is decreased toward its end remote from the power-driven spreadingmachine.

In this case, however, by gradually increasing the diameters of thesmall apertures as they approach to the end of the spreading hose remotefrom the power-driven spreading machine, the decrease of the dischargeof the powder from the small apertures of the spreading hose can becompensated, thereby maintaining a uniform supply or spread quantity ofthe powder per unit area over the whole length of the spreading hose.

That is, when L,, L, L,.= const., the diameters of the small aperturesare gradually and continuously increased as shown by the relation of:

the diameters of the small apertures are increased in step as shown bythe relation of:

d,,,=d,, d,= d,,=d, FIG. 9 illustrates a spreading hose according to thepresent invention in which the diameter of the spreading hose is reducedcontinuously and gradually towards its end remote from the power-drivenspreading machine. As described hereinbefore, the airflow rate in thespreading hose is reduced as the air approaches to the end remote fromthe spreading machine because much air is flown out or dischargedthrough the small apertures of the spreading hose. When the diameter ofthe spreading hose is being reduced continuously and gradually towardsthe end remote from the power-driven spreading machine, the velocitiesof the airflow at various small aperture positions can be maintainedsubstantially equal so that the discharge of the powders may bemaintained constant over the whole length of the spreading hose.

That is, when L,,, L,, L,,= const. and d d, d,, const., the diameter ofthe spreading hose is continuously reduced as shown by the relation of:

D,,, D,, D, 0,.

The spreading hose shown in FIG. 10 has the same outer diameter over thewhole length thereof while the wall thickness of the spreading hose isreduced toward its end remote from the spreading machine.

That is, when L L, =1, const. d d d const., and D,,, D,, D,,, the wallthickness is increased as shown by the relation of".

The air pressure (distribution) within the spreading hose is lowered asthe air moves away from the airflow inlet of the spreading hose.Therefore, when the wall thickness is selected to withstand the abovedescribed pressure, the weight of the spreading hose can be reducedwithout lowering the strength thereof.

A powder-spreading device according to the present invention is mainlyemployed in spreading powder-form agents, but

maybe equally used for spreading the agricultural chemical agentscontaining a large amount of agents in the granular fonn. Theagricultural chemical agents in the granular form have an apparentdensity higher than that of agents in the form of powder so that theforce of inertia of the agents in the granular form is larger.Therefore, an agent in the granular form tends to merely pass throughthe small aperture, and is not ejected or spread. It is, therefore, notpreferable to supply into and spread from a spreading'hose for use inspreading agents in the form of powder the agents in granular form.However, according to the present invention a spreading hose is providedtherein with suitable barriers or weirs so that the airflow carrying thechemical agents in granular form is caused to make wavering and vortexmotions so as to change the directions of the flows of the chemicalagents, thereby effecting the uniform spreading of the chemical agentsin granular form.

FIG. 11 and 12 show the embodiments of the present invention forspreading the chemical agents in granular form in an effective manner asdescribed hereinbefore. in the embodiment shown in FIG. 11, portions,spaced apart from each other by a suitable distance, of the upper orlower sides of the spreading hose are joined and restricted, for exampleby a high-frequency welding machine. Thus, within the passage of thespreading hose 1 are formed the barriers 7,7 so that wavering and/orvortex motions of the air are produced by the barriers 7 and 7'.Therefore, the chemical agents in granular form are carried by thewavering and/or vortex flown or collide against and bound back from thebarriers 7 and 7', and finally discharged or ejected from the smallapertures in a very effective manner.

H6. 12 shows another embodiment of the present invention for use inspreading the chemical agents in the form of granular. lnstead ofreducing the inner diameter of the spreading hose by the provision ofthe barriers as shown in FIG. 11, flat plates 8 made of hard plastic arewelded or bonded to the bottom of the spreading hose 1 so that when theinner pressure is applied to the spreading hose 1 and the spreading hose1 begins to expand, the portions thereof to which the flat plates 8 arewelded or bonded are prevented from expanding, whereby the barriers 9are formed. Small apertures 2 are provided in the sloping surfaces 10 ofthe barriers 9. The chemical agent in granular form can be spreadthrough these small apertures 2 in the same efi'ective manner as in thecase of the embodiment shown in FIG. 11.

In practical use of a spreading device of the present invention, thedevice is normally carried at its opposite ends by two operators, one ofthem carrying a overdriven spreading machine. In case of the length ofthe spreading hose being too long as compared with the width of anobject, such as a rice field, over which the powders are spread, thespreading hose may be positioned angularly of the direction of itsmovement so that the apparent length of the spreading hose may beshortened. Furthermore, when one of the operators who is carrying thepower-driven spreading machine must walk ahead or behind the otheroperator according to the direction of the wind in order that the otheroperator may be prevented from being exposed to the spread agriculturalchemical agents, the spreading hose according to the present inventionmay be disposed angularly of movement so that a safe spreading operationmay be ensured.

Another practical method of using the spreading device according to thepresent invention is to hold a power-driven spreading machine in a fixedposition as a center and to move the closed end of the spreading hoseabout the center, thus defining a circle and thereby spreading thechemical agents in thus defined circular area.

As described in detail hereinbefore, an effective powderspreadingoperation can be accomplished by a simple device of the presentinvention; the spreading hose made of soft material eliminates the fearof the crops being damaged during the powder-spreading operation; andthe length of the spreading hose may be suitably adjusted in accordancewith demand by closing the end remote from the power-driven spreadingmachine at a suitable length therefrom. Thus, it will be readilyunderstood many substantial advantages to agriculture are accrued fromthe present invention.

What is claimed is:

l. A device for spreading a pulverulent agent over the ground in whichdevice air under pressure is used as the medium for transporting thepulverulent agent, comprising lightweight flexible wall means forming anaxially elongated hoselike member open at one end and closed at theother, said wall means being expandable from a collapsed condition whennot in use, in which condition it can be wound in a beltlike manner, toan expanded condition when air under pressure is introduced into saidwall means for forming a continuous flow passage therethrough from theopen end to the closed end, a line of spaced small apertures formedthrough said wall means and extending in the axial direction thereofwith the line of said apertures being substantially rectilinear andlocated in a single plane extending longitudinally through said wallmeans, said apertures forming nozzle openings for discharging air andpulverulent agent, power-driven spreading means for supplying a mixtureof compressed air and pulverulent agent, means for connecting saidpower-driven spreading means to the open end of said wall means forcharging the compressed air and pulverulent agent into the open end ofsaid wall means while the closed end of said wall means remains free sothat the compressed air and pulverulent agent flow through the flowpassage in said wall means and pass outwardly through the flow pasage insaid wall means and pass outwardly through the nozzle openings formed bysaid apertures which are directed toward the ground for spreading thepulverulent agent over the ground, at least one of the diameter of saidwall means the pitch and diameter of said apertures being varied alongthe length of said wall means for effecting substantially uniformdistribution of the pulverulent agent over the ground, and thelightweight flexible characteristic of said wall means being such thatdue to the free closed end of said wall means and the jet action of thecompressed air and pulverulent agent directed downwardly at the groundfrom the nozzle openings formed by said apertures a reaction force isdeveloped capable of lifting said wall means above the ground andmaintaining it in that position during the spreading operation.

2. A device, as set forth in claim 1, wherein the spacing between saidsmall apertures being equal for the extent of said wall means,.and thediameter of the nozzle openings of said small apertures increasing assaid apertures extend away from the open end of said wall meansconnected to said spreading means for supplying compressed air andpulverulent agent.

3. A device, as set forth in claim 1, wherein the wall thickness of saidwall means having a decreasing thickness as said wall means proceedsoutwardly from the end thereof connected to said spreading means forsupplying compressed air and pulverulent agent.

4. A device, as set forth in claim 1, characterized therein by meansforming projections extending inwardly into the flow passage of saidwall means and each said projection being located adjoining anddownstream airflow wise of one of said apertures.

5. A device, as set forth in claim 4, wherein said means formingprojections comprising a member secured to the exterior surface of saidwall means adjacent each said aperture having an adjoining projectionfor forming a projection extending inwardly into said wall means on theside thereof containing said aperture when said wall means is extendedinto the expanded condition providing a flow passage therethrough, theprojection formed by said member providing a sloping surface prior ofsaid wall means and said small aperture being located in the slopingsurface formed by the projection.

6. A device, as set forth in claim 1, wherein the diameter of the nozzleopenings of said small apertures being all equal and the spacing betweenadjacent said small apertures decreasing as said apertures extend awayfrom the open end of said wall means connected to said means forsupplying compressed air and the pulverulent agent.

Patent No. 3,610,530 Dated October 5, 1971 Inventor(s) NAKO SUDA It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In the heading of the patent,

the name of the inventor should read:

--Naka.o Soda-- the name of the assignee should read:

-Mitsubishi Jukogyo Kabushiki Kaisha.

Tokyo, Japan (undivided half)-- Signed and sealed this 2nd day of May1972.

(SEAL) Attest:

EDWARD M.FLE'1CHER, JR. ROBERT GOTTSGHALK Attesting Officer Commissionerof Patents FORM PO-1 0- USCOMM-DC scan-Poo 9 US. GOVERNMENT PRINTINGOFFICE: ll! O3Ifi-3Il

1. A device for spreading a pulverulent agent over the ground in whichdevice air under pressure is used as the medium for transporting thepulverulent agent, comprising lightweight flexible wall means forming anaxially elongated hoselike member open at one end and closed at theother, said wall means being expandable from a collapsed condition whennot in use, in which condition it can be wound in a beltlike manner, toan expanded condition when air under pressure is introduced into saidwall means for forming a continuous flow passage therethrough from theopen end to the closed end, a line of spaced small apertures formedthrough said wall means and extending in the axial direction thereofwith the line of said apertures being substantially rectilinear andlocated in a single plane extending longitudinally through said wallmeans, said apertures forming nozzle openings for discharging air andpulverulent agent, powerdriven spreading means for supplying a mixtureof compressed air and pulverulent agent, means for connecting saidpower-driven spreading means to the open end of said wall means forcharging the compressed air and pulverulent agent into the open end ofsaid wall means while the closed end of said wall means remains free sothat the compressed air and pulverulent agent flow through the flowpassage in said wall means and pass outwardly through the flow passagein said wall means and pass outwardly through the nozzle openings formedby said apertures which are directed toward the ground for spreading thepulverulent agent over the ground, at least one of the diameter of saidwall means the pitch and diameter of said apertures being varied alongthe length of said wall means for effecting substantially uniformdistribution of the pulverulent agent over the ground, and thelightweight flexible characteristic of said wall means being such thatdue to the free closed end of said wall means and tHe jet action of thecompressed air and pulverulent agent directed downwardly at the groundfrom the nozzle openings formed by said apertures a reaction force isdeveloped capable of lifting said wall means above the ground andmaintaining it in that position during the spreading operation.
 2. Adevice, as set forth in claim 1, wherein the spacing between said smallapertures being equal for the extent of said wall means, and thediameter of the nozzle openings of said small apertures increasing assaid apertures extend away from the open end of said wall meansconnected to said spreading means for supplying compressed air andpulverulent agent.
 3. A device, as set forth in claim 1, wherein thewall thickness of said wall means having a decreasing thickness as saidwall means proceeds outwardly from the end thereof connected to saidspreading means for supplying compressed air and pulverulent agent.
 4. Adevice, as set forth in claim 1, characterized therein by means formingprojections extending inwardly into the flow passage of said wall meansand each said projection being located adjoining and downstream airflowwise of one of said apertures.
 5. A device, as set forth in claim 4,wherein said means forming projections comprising a member secured tothe exterior surface of said wall means adjacent each said aperturehaving an adjoining projection for forming a projection extendinginwardly into said wall means on the side thereof containing saidaperture when said wall means is extended into the expanded conditionproviding a flow passage therethrough, the projection formed by saidmember providing a sloping surface prior of said wall means and saidsmall aperture being located in the sloping surface formed by theprojection.
 6. A device, as set forth in claim 1, wherein the diameterof the nozzle openings of said small apertures being all equal and thespacing between adjacent said small apertures decreasing as saidapertures extend away from the open end of said wall means connected tosaid means for supplying compressed air and the pulverulent agent.